Power and data interfaces of mainstream smartphones are being fully converted from micro USB interfaces to USB Type-C interfaces, and structure designs thereof are becoming increasingly compact. A ratio of a screen area to an area of a front surface of a mobile phone body, that is, a screen-to-body ratio, directly reflects a compact degree of a structure design, and is also an important criterion for evaluating, by consumers, whether an appearance of a mobile phone is attractive. Therefore, the screen-to-body ratio has received much attention from mobile phone manufacturers.